A Versatile Vehicle the mysteries of the universe since the repairs and meters) in diameter. The tank weighs a total of 1.68 improvements were made. million pounds (762,048 kilograms) at liftoff. Two in- The first true aerospace vehicle, the Space ner tanks provide a maximum of 145,000 gallons Shuttle, takes off like a rocket. The winged orbiter Satellites today play a major role in the fields of environmental protection, energy, weather forecast- (659,170 liters) of liquid oxygen and 390,000 gallons then maneuvers around the Earth, like a spaceship, (1.773 million liters) of liquid hydrogen. The tank feeds and lands on a runway, like an airplane. ing, navigation, fishing, farming, mapping, oceanog- raphy and many other space-borne applications. Sat- these propellants to the main engines of the orbiter The Space Shuttle is designed to carry large and ellites also provide worldwide communications, link- throughout the ascent into orbit, and is then dis- heavy payloads into Earth orbit. But unlike earlier ing the people and nations of the world together. A carded. manned spacecraft, which were good for only one single channel, one out of 24 on many communica- Most of the Shuttle’s power at liftoff is provided flight, the Shuttle orbiter and solid rocket boosters tions satellites, can provide television coverage to by its two solid rocket boosters. Each booster is 149.1 can be used again and again. most entire nations. Satellites have become an indis- feet (45.4 meters) high and 12.2 feet (3.7 meters) in The Shuttle also provides a new capability, to pensable part of the modern world. diameter, and each weighs 1.3 million pounds repair or service spacecraft in orbit, or return them to All satellites released from a Space Shuttle ini- (589,670 kilograms). Their solid propellant consists Earth for a more extensive overhaul and another tially enter low Earth orbit — about 115 to 250 miles of a mixture of aluminum powder as the fuel, alumi- launch. The Long Duration Exposure Facility (LDEF), (185-402 meters) altitude. Some, such as Hubble or num perchlorate as the oxidizer and iron oxide as a a free-flying payload, remained in orbit almost six catalyst, all held together by a polymer binder. Flight the environment-monitoring Upper Atmosphere Re- The orbiter Columbia returns to Kennedy’s Shuttle Landing years before it was recovered and returned to Earth, search Satellite, remain there throughout their work- Facility, completing Mission STS-62 on March 18, 1994. All experience indicates they produce about 2.908 mil- where it yielded a wealth of new data on the space ing lives. four orbiters in the Shuttle fleet are now equipped with a lion pounds (12.935 million newtons) of thrust each environment. An INTELSAT commercial communica- drag chute that is deployed during landing to assist in stop- for the first few seconds after ignition, before gradu- tions satellite stranded in a useless orbit was retrieved Many spacecraft, such as the weather and com- ping and to provide greater stability in the event of a flat tire ally declining for the remainder of a two-minute burn. in dramatic fashion by Shuttle astronauts, repaired munications satellites that can “see” a third of the or steering problem. Together with the orbiter’s three main engines firing and then re-boosted to its proper orbit to begin op- world at once, operate at a much higher level known at 104 percent, total thrust of the Space Shuttle at eration. The Hubble Space Telescope was success- as geosynchronous orbit. This is a flight path about liftoff is 7.0175 million pounds (31.2 million newtons). fully serviced in orbit and has helped unlock many of 22,300 miles (35,888 kilometers) above and aligned covery, Atlantis and Endeavour (Challenger’s replace- with the equator, with a speed in orbit that matches ment). In-orbit maneuvering capability is provided by that of the Earth’s surface below. From the ground two smaller Orbital Maneuvering System (OMS) en- such satellites appear to hang motionless in the sky. gines located on the orbiter. They burn nitrogen tetrox- Spacecraft reach this altitude by firing an attached The Parts of the Space Shuttle ide as the oxidizer and monomethyl hydrazine as the fuel, from on-board tanks carried in two pods at the propulsion unit, such as an Inertial Upper Stage (IUS), On the first Space Shuttle flight — STS-1 in 1981 — Pilot The flight components of the Space Shuttle are upper rear. The OMS engines are used for major ma- or the smaller Payload Assist Module (PAM), after two solid rocket boosters, an external tank and a Robert Crippen floats effortlessly in the microgravity of deployment from the Shuttle orbiter. At altitude an neuvers in orbit, and to slow the vehicle for re-entry space, inside the middeck of the orbiter Columbia. winged orbiter. The assembled Shuttle weighs about at the end of the mission. on-board engine fires to “circularize” the orbit. 4.5 million pounds (2.041 million kilograms) at liftoff. off-duty crew members, called the middeck, is located Sometimes interplanetary explorers, such as the The orbiter carries the crew and payload. It is below the flight deck. It contains pre-packaged food, Magellan mission to Venus or the Galileo mission to Crew Accommodations 122 feet (37 meters) long and 57 feet (17 meters) a toilet, bunks and other amenities. Experiments for Jupiter, are launched from the Space Shuttle. They high, has a wingspan of 78 feet (24 meters), and Nominal crew size for a Shuttle flight is up to the flight also may be stowed in middeck lockers. also use the IUS to exit Earth orbit and begin their weighs from 168,000 to 175,000 pounds (76,000 to seven people; 10 could be carried in an emergency. journey to Earth’s planetary neighbors. 79,000 kilograms) empty. It is about the size and gen- A typical Shuttle crew includes a commander and The crew occupies a two-level cabin at the forward pilot, mission specialists and sometimes payload spe- eral shape of a DC-9 commercial jet airplane. Orbit- end of the orbiter. They operate the vehicle from the The ability of the Shuttle to land on a runway, cialists. The commander and pilot are selected from ers may vary slightly from unit to unit. upper level, the flight deck, with the flight controls for unlike the expensive parachute descent and recov- the pilot astronaut corps, highly qualified individuals ery at sea techniques used in the Mercury, Gemini The orbiter carries its cargo in a cavernous pay- the mission commander and pilot located in the front. with at least 1,000 hours pilot-in-command time in jet and Apollo human spaceflight programs, saves both load bay 60 feet (18.3 meters) long and 15 feet (4.6 A station at the rear, overlooking the payload bay aircraft who also must meet other rigorous qualifica- through two windows, contains the controls a mis- time and money. In addition, again unlike prior meters) wide. The bay is flexible enough to provide tions. Mission specialists are scientists, physicians sion specialist astronaut uses to operate the Remote manned spacecraft, the most expensive Shuttle com- accommodations for unmanned spacecraft in a vari- or other highly qualified specialists. ponents can be refurbished and made ready for an- ety of shapes and sizes, and for fully equipped sci- Manipulator System arm which handles elements in other launch. The complex and expensive orbiter is entific laboratories such as the Spacelab or the payload bay. Mission operations displays and con- Payload specialists are persons other than NASA designed to last 100 flights minimum, and the solid SPACEHAB. Depending on the requirements of the trols are on the right side of the cabin, and payload astronauts — including foreign citizens — who have rocket booster casings, engine nozzles, parachutes, particular mission, a Space Shuttle can carry about controls on the left. The latter are often operated by specialized onboard duties. They may be added to etc., for 20 launches. Only the external tank is ex- 37,800 pounds (17,146 kilograms) into orbit. payload specialists, who are usually not career NASA Shuttle crews if activities that have unique require- astronauts. The living, eating and sleeping area for ments are involved. pended on each flight. The high cargo capacity and An orbiter is equipped for flight with three main major component reusability of the Shuttle make it engines, each producing 400,500 pounds (1.781 mil- unique among space vehicles. lion newtons) of thrust when operating at 104 per- Orbiter Insulation The orbiter is the only part of the Space Shuttle cent at liftoff (at sea level). This figure is derived from which has a name in addition to a part number. The flight experience and is about 2.7 percent better than A special silicon-based insulation in the form of 100 square-inch (average) tiles serves as the pri- first orbiter built was the Enterprise, which was de- the required design minimum. The engines burn for mary heat shield for the orbiter. This material sheds heat so readily that one side can be held in bare hands The Shuttle’s usefulness as a platform for on-orbit servic- signed for flight tests in the atmosphere rather than over eight minutes, while together drawing 64,000 while the opposite side is red-hot. These lightweight tiles are made to survive temperatures of up to 1,260 ing of spacecraft was demonstrated during the STS-61 gallons (242,240 liters) of propellants each minute degrees Celsius (2,300 degrees Fahrenheit).